CN1006606B - Roller for pipe-hot rolling mill with 3 rollers - Google Patents

Abstract

The present invention provides a new roller shape of a three-roller pipe rolling mill for hot rolling, which is composed of a diameter reducing section, a wall reducing section, a reeling section, a release section and a circle gauging section. In the present invention, the corresponding roller shape can be obtained from a theoretical calculation formula according to actual demand, or reformation can be performed on the existing roller of a three-roller pipe rolling mill. A roller designed according to the roller shape of the present invention is used for a three-roller pipe rolling mill group, and as compared with the three-roller pipe rolling mill group designed according to the technological characteristics of advance angle variation, pore throat raising, rolling speed reduction, etc., has the advantages of reduced device investment, simplified device structure and rolling process, prolonged service life of the roller, high product quality and production rate of the rolling mill, and great economic benefit.

Description

Roller for pipe-hot rolling mill with 3 rollers

The invention provides a kind of new roll forming of hot seamless tube machine, particularly a kind of new roll forming that is used for three-roll pipe mill.

At present, along with iron and steel, machinery and war industry are growing, the three-roll pipe mill as producing one of seamless pipe capital equipment reaches its maturity.Since U.S. W.J. A Saier (Assel) invented the A Saier three-roll pipe mill in 1932, its roll forming (shown in Figure 13,14) was used till today always.This roll forming is formed by four sections: 1, sizing reduction section (claiming the section of nipping again), the main effect of this section is tube reducing and tube wall is carried out a spot of compression, to produce the enough power that draws into the rolled piece roll of nipping, this section roll forming is made of straight line, and the angle between straight line and rolling centerline is very little; 2, wall-reducting section (claiming A Saier shoulder or compression section again), this section mainly play and subtract the wall effect, to obtain needed wall thickness, this section roll forming constitutes by two circular arcs are tangent, angle is 51 ° between two circular arc tangential lines and rolling centerline, or tangent by two circular arcs and a straight line, angle α between straight line and roll axis ₂With roll off angle φ sum, be angle between this straight line and rolling centerline, equal 40～50 °.3, in U.S. Pat-4392369 specification, angle is approximately got 30 ° between wall-reducting section straight line and rolling centerline.3, expansion section (claiming the press polish section again), the main effect of this section is to make thickness of pipe wall even, and the tube wall surface quality is played a crucial role, and this section roll forming mainly is made of straight line, and the angle between straight line and roll axis equals roll off angle φ; 4, round gauge section (claiming outlet section again), this section can make the pipe rule circle behind the expansion, can produce a small amount of hole enlargement, are beneficial to the depoling rod, and this section roll forming is made of straight line, and angle is generally 2～4 ° between straight line and rolling centerline.This roll forming structure of existing three-roll pipe mill, easily make and occur tail three angular rolling card phenomenons in the operation of rolling, therefore limited this machine production range, make it only to be used for rolling thick-walled pipe, can not be used for rolling external diameter and wall ratio greater than 12 light-wall pipe, because this roll forming axial slip coefficient is little, can not realize that big lengthening coefficient is rolling, hole enlargement is little when rolling thick-walled pipe, the rod of loosing core is difficult, be subjected to rolled piece tail three angular rolling impact cards when rolling, can only select less feed angle and lower roll revolution for use than light-wall pipe.Therefore, these faults of construction of roll forming make roll wear serious, not only increase the wall thickness tolerance and the inside spin road degree of depth, influence the surface quality of tube wall, and reduce roll service life and rolling rate.When tail three angular rolling cards particularly occurring, both influenced normally carrying out of the whole operation of rolling, fragile again equipment.For this reason, on special Lanace Wa Er (Transval) three-roll pipe mill that France succeeds in developing, started with from reducing feed angle, increase tail end wall thickness and reduction mill speed, when utilizing light-wall pipe to be rolled to afterbody in 1967, the revolution memorial archway of fast rotation milling train prevents tail three angular rolling card phenomenons.In addition, the method for utilizing hole-lifting throat is arranged also, control the generation of tail triangle.But, because the time of hole-lifting throat is difficult to accurate control, be difficult for recovering the pore throat original position, the caliber and the wall thickness tolerance that shut out are increased.The rolled piece that utilizes above-mentioned way to make is given next procedure, for example draws and dials, and brings very big difficulty, and increases the percent defective of product.Although people constantly make great efforts to design different device structures, try hard in the operation of rolling, control the generation of tail triangle, but, can only increase the investment that makes device structure complicated, can not fundamentally solve the various defectives that present three-roll pipe mill exists, also can't satisfy the production requirement that enlarges kind.

The purpose of this invention is to provide a kind of roller for pipe-hot rolling mill with 3 rollers, but this roll forming is simplified apparatus structure and rolling mill practice process not only, and obviously reduce the wall thickness tolerance and the inside spin road degree of depth, and increase lengthening coefficient, significantly improve roll service life and rolling rate.

The object of the present invention is achieved like this: new roll forming is designed to five sections, i.e. sizing reduction section, wall-reducting section, expansion section, releasing section, round gauge section.Wherein sizing reduction section and round gauge section adopt the corresponding roll forming of existing three-roll pipe mill roll, so that simplify the complete machine structure design.The wall-reducting section that newly is designed to, expansion section, releasing section characteristics are as follows: wall-reducting section mainly is made of straight line, and angle is less than 40 ° between this straight line and rolling centerline; Expansion section is made of straight line or curve, can use curve when feed angle during more than or equal to 12 °, and curve shape can utilize straightener roll forming computing formula to derive.When feed angle adopts straight line during less than 12 °, included angle between straight line and roll axis ' generally be not equal to the roll off angle φ of existing three-roll pipe mill, φ ' can try to achieve by theoretical calculation formula.Be right after expansion section and be provided with releasing section, this section mainly is made of straight line, and angle is bigger 3～15 ° than angle between the straight line of round gauge section and rolling centerline between straight line and rolling centerline.With each section line segment of sizing reduction section, wall-reducting section, expansion section, releasing section and round gauge section, connect to form new roll forming successively by the circular arc slyness.For making new roll forming be more suitable for demand of practical production, releasing section and round gauge section can be integrated, also can make new roll forming only contain in wall-reducting section, expansion section, the releasing section one section or two sections, other each section adopts the line segment of existing three-roll pipe mill roll correspondent section, then each line segment is connected by circular arc is slick and sly.

Roll according to the new roll forming design of the present invention is used for the three roll pipe unit, compare with the three roll pipe unit that designs according to process characteristics such as change feed angle, hole-lifting throat, reduction mill speeds at present, can reduce equipment investment, simplified apparatus structure and rolling mill practice process.The new roll forming axial slip of the present invention coefficient is big, can increase lengthening coefficient, can use big feed angle and higher roll revolution rolling, thereby mill speed is fast, can significantly improve roll service life and Rolling Production rate; Can rolling external diameter and the light-wall pipe of ratio D/S≤20 of wall thickness, the tube wall surface quality is good, can reduce the wall thickness tolerance and the inside spin road degree of depth significantly; Especially can eliminate tail three angular rolling card phenomenons, not only can prevent the damage that therefore equipment cause, and, for example draw and dial next process, advantageous particularly both can reduce to draw and dial number of times, increased and drew tube pulling length, can improve the utilization rate and the product qualified rate of material again, cut the waste, reduce product cost.Utilize the design feature of the new roll forming of the present invention, transform the roll forming of existing three-roll pipe mill, also can reach simplified apparatus structure and rolling mill practice process, improve the quality of products, significantly improve the purpose of economic benefit.

Below in conjunction with accompanying drawing the present invention is further described:

Fig. 1 is the half sectional view of a kind of concrete structure of the present invention.

Fig. 2 is the left view of Fig. 1.

Fig. 3～12nd, roll forming structural representation of the present invention.

Figure 13～14th, existing three-roll pipe mill roll forming structural representation.

Figure 15 is the partial enlarged drawing of Figure 13.

Figure 16 is the partial enlarged drawing of Figure 14.

Shown in Fig. 1～16, describe concrete structure of the present invention in detail.The new roll forming of hot roll pipe mill of the present invention requires to be designed to five sections according to rolling mill practice: L ₁Be sizing reduction section, L ₂Be wall-reducting section, L ₃Be expansion section, L ₄Be releasing section, L ₅Be round gauge section.Wherein the roll forming of two sections of sizing reduction section and round gauge sections is the characteristics design that makes full use of existing three-roll pipe mill roll forming correspondent section, can the simplified apparatus structure Design, particularly be beneficial to the transformation existing equipment.All the other each sections are designed to following form: wall-reducting section mainly is made of straight line, angle α between straight line and roll axis ₁And roll off angle φ sum is angle between this straight line and rolling centerline, and this angle is less than 30 °.This section roll forming has fundamentally changed the steeper roll forming of existing A Saier shoulder; Expansion section is made up of straight line or curve, can use curve when feed angle during more than or equal to 12 °, and curve shape mainly utilizes straight machine roll forming computing formula to derive.When feed angle adopts straight line during less than 12 °.The existing three-roll pipe mill roll off angle φ of included angle between this straight line and roll axis ' generally be not equal to, this included angle ' theoretical calculation formula as follows: tg φ '=A/B, wherein:

$\mathrm{A=}\frac{{\mathrm{L·Sin}}^2{\mathrm{F·Cos}}^{2}F}{\sqrt{D^2{\mathrm{+L}}^2{\mathrm{·Sin}}^2{\mathrm{F·Cos}}^{2}F}}\mathrm{(1-}\frac{R}{\sqrt{D^2{\mathrm{+L}}^2{\mathrm{·Sin}}^{2}F}}\mathrm{)+}$

${\mathrm{R·L·Sin}}^2\mathrm{F·}\sqrt{\frac{D^2{\mathrm{+L}}^2{\mathrm{·Sin}}^2{\mathrm{FCos}}^{2}F}{{\mathrm{(D}}^2{\mathrm{+L}}^2{\mathrm{Sin}}^2{\mathrm{F)}}^3}}$

${\mathrm{B=Cos}}^2\mathrm{F+(1-}\frac{L^2{\mathrm{Sin}}^{2}F}{D^2{\mathrm{+L}}^2{\mathrm{·Sin}}^{2}F})\frac{{\mathrm{RSin}}^{2}F}{\sqrt{D^2{\mathrm{+L}}^2{\mathrm{·Sin}}^{2}F}}$

L＝ (h _oSinφ)/(Cos ²·Sin ²G+Som ²φ)

$\mathrm{D=}\sqrt{L{}^2\mathrm{·Cos}{}^2\mathrm{\phi ·Sin}{}^2{\mathrm{G+(h}}_o\mathrm{-L·Sin\phi )}{}^2}$

F＝arc Cos（CosG·Cosφ）

Wherein: R-plug radius and tube wall S sum

h ₀-roll axis and roll stand frame centre of gyration line intersection point are to the distance of rolling centerline

φ-when the roll stand frame corner is zero, angle between roll axis and rolling centerline

The angle of revolution of G-roll stand frame

This section roll forming improves the tube wall surface quality and cuts much ice for reducing the rolling seamless pipe wall thickness tolerance and the inside spin road degree of depth.Releasing section mainly is made of straight line, and angle is bigger 3～15 ° than angle between the straight line of round gauge section and rolling centerline between straight line and rolling centerline.This section is arranged on after the expansion section, and before the round gauge section, main purpose is to reduce rule circle amount.Each line segment that to form sizing reduction section, wall-reducting section, expansion section, releasing section, round gauge section successively is by be combined into new roll forming of the present invention slick and sly connection of circular arc.

The new roll forming of the present invention can be made one section or two sections new roll forming only containing in wall-reducting section of the present invention, expansion section, the releasing section according to needs of production.Like this, the roll of existing three-roll pipe mill is changed a social system, simplified its device structure and rolling mill practice process, can reduce scrap build investment, give full play to the potentiality of existing equipment, increase economic efficiency significantly existing three-roll pipe mill with regard to being very beneficial for.

Claims (4)

1, a kind of hot rolling three-roll pipe mill roll by each section line segment of sizing reduction section, wall-reducting section, expansion section and round gauge section, by combining slick and sly connection of circular arc, is characterized in that successively:

1.1 wall-reducting section mainly is made of straight line, angle is less than 30 ° between straight line and rolling centerline.

1.2 expansion section mainly is made of straight line, straight line and rolling in the heart angle α utilize following formula down to obtain:

Tg α=A/B, in the formula:

$\mathrm{A=}\frac{{\mathrm{L·Sin}}^2{\mathrm{F·Cos}}^{2}F}{\sqrt{D^2{\mathrm{+L}}^2{\mathrm{·Sin}}^2{\mathrm{F·Cos}}^{2}F}}\mathrm{(1-}\frac{R}{\sqrt{D^2{\mathrm{+L}}^2{\mathrm{·Sin}}^{2}F}}\mathrm{)+}$

${\mathrm{R·L·Sin}}^2\mathrm{F·}\sqrt{\frac{D^2{\mathrm{+L}}^2{\mathrm{·Sin}}^2{\mathrm{F·Cos}}^{2}F}{{\mathrm{(D}}^2{\mathrm{+L}}^2{\mathrm{·Sin}}^2{\mathrm{F)}}^3}}$

${\mathrm{B=Cos}}^2\mathrm{F+(1-}\frac{L^2{\mathrm{Sin}}^{2}F}{D^2{\mathrm{+L}}^2{\mathrm{Sin}}^{2}F})\frac{{\mathrm{RSin}}^{2}F}{\sqrt{D^2{\mathrm{+L}}^2{\mathrm{Sin}}^{2}F}}$

2, roll according to claim 1 is characterized in that can being provided with releasing section between expansion section and round gauge section.

3, roll according to claim 2 is characterized in that releasing section mainly by rectilinear(-al), and angle is bigger 3～15 ° than angle between the straight line of round gauge section and rolling centerline between this straight line and rolling centerline.

4, roll according to claim 1 is characterized in that expansion section can adopt curve when feed angle during greater than 12 °, and this curve utilizes straightener roll forming computing formula to obtain.

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